Tools & Microfiber2 min read

Calibration As-Found and As-Left Data: Review Both for Coating Instruments

As-found data describe an instrument's condition before relevant service or adjustment; as-left data describe its condition afterward. Both can matter when reviewing coating measurements made before the instrument was serviced.

Updated · NANOLAB Knowledge

The key distinction

Fluke identifies these records in calibration reporting. A satisfactory as-left result does not automatically explain whether earlier measurements were affected by an as-found deviation. The responsible measurement process should assess that question.

Practical checks

  1. Request the appropriate calibration data with the service.
  2. Review any as-found deviation against the instrument's use history.
  3. Record the decision about affected measurements and future use.

Example

Illustrative example: an instrument returns within specification after adjustment, but its initial readings were outside the agreed limit. The earlier test records may need review rather than being accepted solely from the final certificate.

Scope and limits

Do not invent a correction for historical data. Qualified technical assessment should determine the actual impact and required response.

Related guidance

Technical references: Fluke: calibration service levels. These sources describe their stated methods or products; they do not certify NANOLAB products or establish compatibility with an unlisted surface.

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.